The present invention concerns an automatic sensor position recognition system. The present invention also concerns a method for automatically recognizing the position of a sensor on a person's body and the use of such a system.
Upper and lower limb impairments are among the most common forms of neurological deficits after a stroke. Patients suffer from insufficient coordination capabilities and weak muscles. Other conditions that may be treated are cognitive defects, vision impairments and speech problems. Some of the relevant therapeutic procedures can be executed at home, under remote supervision.
In order to evaluate the motor performance of the patient and provide appropriate feedback, data about the patient's movements are required. To this end, sensors or markers are attached to the patient's body at different locations. While the absolute orientation of the sensors or markers that are used can be determined, their absolute position in space cannot be determined. For transforming the orientation measurements into body movements and postures it is therefore necessary to know the body segment which a sensor is attached to.
Currently, this information is provided manually to a data processing unit by associating the body segment with the unique sensor identification. This procedure is always required when the sensors are attached to the body. Since it requires human interaction it is not only error-prone but is also an obstacle particularly for impaired patients when using such a system.
WO 2004/053444 discloses a system and method for monitoring the body temperature of a person. The system comprises one or more sensor devices, where each sensor device is capable of measuring a temperature at a known location of a body of a human or other animal. Each sensor transmits a temperature measurement value and sensor identification to a monitor device. The monitor device receives the temperature measurement value and sensor identification, and computes an adjusted temperature value based upon the position of the measuring sensor, body age, and time of age. As the sensors report a different temperature depending on their location on the body, the importance of assigning a measured temperature to an individual sensor is stated. This is undertaken using a sensor registration table comprising a sensor identification number, a unique sensor registration number assigned during sensor manufacture, a sensor position indicator, body age, and upper and lower alarm limits. Thus, the information has to be entered manually with the associated drawbacks.
From the above it is apparent that a need still exists in the art for an automatic sensor position system and a method for automatically recognizing the position of a sensor on a person's body.